Residual Wood Study • Objective: Estimate and compare the range of variability in the origin, abundance and condition of deadwood material and live trees recently disturbed by wildfire and by clearcut harvesting
7 study areas • 1 Mountain wildfire – 34 yr
• 3 Foothills wildfires – 35 - 40 yr
• 3 Foothills harvests – 23 - 27 yr 0 N
50
100 Kilometers
Paired design • Example of 2 sites: • Lynx Creek Burn (35 yr) & Adjacent cutblocks (23-27 yr)
## # S # # #
#
# S # # SS S#
# #
#
# ##
# S## SS # S S ## S # S
# #
#
#
# S
#
# #
# #
#
# # ##
#
# S
# ## #
# # S
• 30 plots per site randomly located (almost)
Lynx Creek 0
5
# S # S
10 Kilometers
S # S # # S # S S#
# S # S ## S S # S
# S
# S
# S
Plot layout down deadwood standing dead standing live 390 m2
30 m
Wood present before disturbance No. pieces of down deadwood
(> 7 cm diameter) 100
Burned Logged
75 50 25 0 0
10
20
30
Time since disturbance (yr)
40
Wood generated after disturbance No. pieces of down deadwood
(> 7 cm diameter) 100
Burned Logged
75 50 25 0 0
10
20
30
Time since disturbance (yr)
40
Mean number of pieces per plot
Decay pattern of down wood
Burned
20 10 0 Logged
20 10 0 1
2
3
4
Log decay class
5
• In burns, hard logs are abundant 35 years after fire; probably recruited fromPre-disturbance falling snags. Post-disturbance
• In cutblocks, most logs are soft 25 years after logging.
30 20 10 0
Burned
30 20 10 0
Logged
• In burns, falling snags get “hung up” above the ground. Pre-disturbance
010 10 -2 0 20 -3 0 >3 0
Post-disturbance
0
Mean number of pieces per plot
Vertical distribution of down wood
Piece height (cm)
• In cutblocks, most logs are flush with the ground.
Summary: Residual wood • Burned stands (35 - 40 yr) – wood carried over from previous stand was highly variable, occasionally abundant • few standing dead trees • occasionally abundant down wood
• Logged stands (23 - 27 yr) – less (and less variable) wood carried over from previous stand • very few standing dead trees • fewer pieces of down wood